Triggering means for color television tube



June 2l, 1960 G. sLEEPER, JR

TRIGGERING MEANS Foa coLoR TELEVISION TUBE Filed March 1, 1954 3 Sheets-Sheet 1 |||||||l| IIIIIIIIII 2 9 1/ lull L au INVENTOR. BYCuEoRc-,E [-.LEEPER 3R. WML

June 2l, 1960 G E SLEEPER, JR

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TRIGGERING MEANS FOR COLOR TELEVISION TUBE 3 Sheets-Sheet 3 Z2 25 '2dP 25 f f f PULSE Y summe VELAY VELAY VELAY AMDLNHER +500 voL-rs Z6 /27 f28 .MORE THAN ANODE AMD AMD AMP Q 19 fQ [30 3\ #vim- REV VlVEo REV BLUE VlVEo BLUE GREEN VIVEO @VEEN SLENAL mEuT SWC 5\ENALmuuT WTC WAAL um SWC 79'] '22A 25A 24A 25A (EAA m 2E Msg f f A snAmNG VELAY. VELAY VELAY AMDL\F\ER "26A '27A 2BA +500 voLT f f MORE THAN ANoVE- AMV AMD AMV 59 40 4\ fzsA 50A [3u REV vlVEo REV BLUE VIDEO BLUE GREEN v|VEo @VEEN E sxcmAL mm SWTC HALmEu 5ml meNALmvuT SWW J 7A I I INVENTolE @EOVGE E. SLEEPER "JR,

BY mim@ V@ ATTORNEYS TRIGGERING MEANS FOR COL'OR TELEVISION TUBE Georgen. sleeper, Jr., 730 Grizzly Peak Blvd.,

'Y Berkeley, Calif.

. Filed Mer. 1, 1954, ser. No. 413,154

tclaim's. (ci. 315-12) Itis generally accepted that the transmission of images in substantially their natural color requires that Ythe image to betransmitted be divided, not only into'its imageelements; but also into selected component color images. o

Heretofore, good results havelbeen obtained through the use of two different types' ofsystems.V One employs separate channels to transmit the separate component color image representative signals'. This system is popularly known as the simultaneous type system. Another system is generally known as vthe sequential type system. This system usesasingle channel to transmit' component color image signals sequentially. Neither system is acceptably compatible with lblack and white reproduction standards. v l g At the present time, therefore, (these-called compatible' system of transmission has been adopted as standard for the United IStates.I In thecompatiblesystem, vcolor transmission is accomplished by reducing 'the'fthreefsimultaneous image representative signals' into'` two simultaneous signals. Onesignal-supplies the brightness component` and the other signal supplies the chroma component. The signal also includes a component providingadditional synchronizing information and' is'ordinarily referred to as the-color burst.1-'Prior to transmission overthe air these several signals are combined'into Va ycomp `site-sig nal. The composite signal includes the brightness component, the chroma' "component, and the synchronization or color burst signal. f j

The receiver adds Vthe lbrightness componentand the chromaV 'component to reproduce' thethree simultaneous`- color imagerrepresentativesignals which are used for reproduction ofthe colored picture Vin the picture tube.

Receivers `adapte'dto Y reproduce such signals are well known in the art-land' are 'not described herein.

There are at presenttvvo` common types of picture;

tubesadapted'for use infsuchreeivers'.'A One is the three' gun tube in which thethreeprimary color signals are reproducedsimultaneously; The other is' v`a single-gun? picture tube in which" the color signalsare changediby time delay circuitsand usedV sequentially.` The nature, construction andV modeyof operation of these `tubesis well-knownfpin the art and is, notdescribed Yin detail in thisspecication. This invention relates specifically to an improved form of picture tube .overcoming the well-known problems inherent in themanufacture, structure and operation of the existing tubes. Y 4 A primary object of this invention is to provide an improved picture tube utilizing secondary emission produced by the-electron impact of a scanning beam to form a pulse for controlling-the action of a circuit and the uorescence of the tube.

Another object of this invention isto provide a colorV nited States Pant ice television picture tube having afar' greater simplicity than has heretofore been known in the art.

The foregoing and further objects of the invention will become apparent to those skilled in the art by an understanding of the following `specification and thev accorti-y panying claims. e -r Fig. 1 is a schematic longitudinal sectional view through one embodiment of a tubeutilizing the present invention in a single gun tube; e

. Fig. 2 is an interior elevational View of the image screen illustrated in Fig. 1 taken on the rline 2-2 of Fig. 1, but showing the lines of the screen greatly enlarged;

Fig. 3 Iis a cross-sectional view of the image screen illustrated in Figs. 1 and 2 looking downwardly on the lineA 3`3 of Figi; e 1

Fig-4 is a schematcflongitudinal, ysectional pespecf i tive view through anotherv embodiment o f a tube utilizing the .present invention in a' three gun tube; `"Fig -5 isaniiiterior elevational view of va form ofA iniageiscreen whichimay-be used as an alternative for thatshown in Fig. 2;-

o l Fig. 6-is a` cross-sectional view of the image screen illustrated in Fig. 5 looking downwardlyon the lines 6-6' ofFig. '5;y -l .r: v Fig. '7 isa schematic` longitudinal view through 'anotherembodiment of a tube 'utilizing'the present invention; Fig; 8 is an interior elevational View of a secondary emission collector illustratedjfin-Fig. 7 taken onthe line 8"-sorrig7rvrusing the presentf'inventiong'and Fig. ll isa schematic-block diagram of circuit means to jfluofesce upon electron limpact inF each fofV like elements 9,'10iand I1 lformin'ga built 't'.argetarea-If The target elements of each series areof` materials f adapted" l 4kderermioeajnumberof comportent Y-colors 'to pro'vrde'fd art, examples being found in United States Letters Patent This inventionis directed'pr'imarilytoward the pro-A vision "'f'a pulse-formingimex'nber 4con`s isting o'f a seco'ndaryfemissionk producing means and Asecondary ernis;`

sion c'ollecting means for controlling 'the'etime periods' during 'whichfsignals' representative 'of the several cornponent colors' are applied to cor'lt'roltheimagej.` re'pr'oV duction. ;`h' 'j l By'way of selected' example, afnitrofcelllosehulz (see Fig. 3) isA deposited. evenly over the phosphors making up the strip-like elements 9, 10 and 11 comprising the image screen 8. Over this nitro cellulose film there is deposited a film. of aluminum of minutclthicknesss, say in the range of millionths. of.v an inch-justthick enough to reflect the light produced by the phosphors, but thin enough to let the electrons pass through.

This procedure is well-known to the-art` andis commonly" However, in the selectedj'emf known as aluminizing bodiment, this film of aluminum does not extendover theentire screen, but it is formed in a series of strips having exact registry with one of the. repeating, seriesv of strip-like elements 49, 10 and' 11 forming.r the built-up target. area.

In. the* selected embodiment of. this invention,. this series of strips is shown in. registry with` the. strip-likeelement itformingV the red seriesV of fluorescent phosphors.

Strips 13 produce secondary emissions each. time the' scanning beam passes over them.' These emissions; as 'later shown in this-specification, are collected andI are.

used for the pulse-forming impulses. There'are many materials which may beused` for secondary emission.' ItA will be observed that aluminumisselected, for example,

for this secondary emission-producing. elementy andrthat l ring 14(see Fig. 1) located inthe flaring'bell'portionv 4 of the tube. This annular ring lrisrpreferably located out of the direct path of the scanning beam. TheV sec- Yondary emission-collecting means is insulated from the anodev 15 of the tube by means of an insulatingV member 16. I l

Thesevcral: strips 13 are connected together andare connected to the anode 15 of the tube.

A terminal 17 is connected tojthe collector 14.for electrically connecting thecollector tol an amplifying circuit. Similarly an anode terminal 18, a grid terminal 19 and the othery requisite terminals are provided in the usual well-known manner.Y

Each time the scanning beam of the tube 1v traverses'.

across a red=aluminized strip' section ofthe tubeV 1, the major .part of Vthe energy is converted into` color energy and light in the phosphor, and the balance causes,Y secondary emission. These secondary emissions in 'turn' are collected by the collector 14 and they producea pulse of current each` time the scanningbeam crosses a metalized stripe in the tube` 1.

CollectorY 14 is maintained at a positive,potential.,sufii-` i -ciently high to attract Vthe secondary emissions from thev metalliestrips associated with the-redrcolor` sections, but

insufliciently high `todeiiect thescanningv beam withinthe tube 1. A positiveA potential of approximately 300 volts` more than the anode voltageproducesthis result.

The signal pulse voltage developed across the resistor 2|)v by the secondary emission current from collector 14- is applied from terminalv 17 through condenserv 2L to a kpulse-shaping, or clipper, amplifier ,22r and mayY be vhandledin the same manner` as the-pulses'illustrated and described in the P. K. Weimer Patent'2,545,325.

After the signal hasY :been suitably amplified and shaped. in the amplifier clipper, itis. applied to signal switchesfor operating thecontrolgrid of. thepicture tube to -gatethe proper. color videosignal in time with the travelv ofthe electronbeam. Any of several well-known means vmay be used. vFor example, themanner'illustratd and describedinthe P; K. Weimer` Patent No. 2,545,325;

Insuch .a system, .pulse delay means, Z4and-25 provided to delay the pulse for controlling each ofthe three video signals. These means may take any of the well-known forms, such as, for example, the pulse delay arrangement suggested in the article entitled Video Delay Lines, appearing in Proceedings of the Institute of Radio Engineers, for 1947 beginning at page 1580.

Pulse amplifiers 26, 27 and 28are provided to control switches orfgates 29, 30 and' 31,A so thatv at any one time only one of the component" color video signals is passed to the grid 6 of projection ktube 1.

Although not shown, the' red, green and blue video signals may be obtained from any suitable color television signalv receiver such as that shown and described, for example, in an article. entitled An Experimental Simultaneous Color Television System, appearing in `Proceedings of the Institute of Radio Engineers," beginning on page 861, for September 1947.

The switch 29passes the red signal to grid 6 during theinterval of time that the scanning beam of projection' tubel passes. the red section.9 to produce a spot of light in the red section of screen 8. Likewise, switch 30 is made operable to pass the greenvideo signal during that timeinterval in which the spot caused by the scanning.

beam ofprojection tube 1 is traversing blue section 10 of the projection screen 8. Similarly, the green signal isI passed through switch 31 to the control electrode 6 of the. projection'tube 1 during the time intervals that the' u spot is traversing the green sections 11 of screen 8.

s It is important that the beam have sufficient threshold intensity to create secondary emissions at all times, but

insufficient intensity to excite the phosphors unless there:

is'a color signalY impressed upon the beam.

and analogous circuit arrangements are equally adaptable for the so-called three gun tube. In such tubes one electron gunisusedfor exciting `the red phosphors, a second forexciting the green phosphors and a third for exciting the blue phosphors. In the selected embodimentof this alternate form of the applicants invention (see Fig. 4),V the picture tube is unchanged with the exception of the substitution of three electron guns for the single elec tron gun disclosed and used in connection with the embodiment illustratedr in Figs. l, 2 and 3. Y Duringv the operation` of sucha tube, the three electron beams are focused andaligned so thatV thefred beamv33 (see Fig. 5) forms aspot34' on the screen 8, theY green beam 35 forms a spot `36. and the blue beam 37 forms a spot 38. In focussing and aligning the beams upon the screen 8a of. the tube, the spot 34-produced by red beam 33 is arranged to precede` the spots 36 and 38 in their normal travel across.

Turning -to the suitable circuit for this arrangement.

(Eig. 1.1), the shaper. or clipperv amplifier delaymeans and switching` means operate in the same manner as that depicted above. The circuit illustrated in Fig. ll corre spends to thatshown in Fig. 10 with the exception of `suf- 11(b) correspond to the color elements 9, 10 and 111`I illus fixes. (a) applied to the reference numerals.

VThe output from. switch 29(11) is applied to the grid 39 supplying the signal for red beam 33. The output of switch 30(0) is applied to the grid 40 supplying the blue signal 38, and the output of the green switch 31(a) is applied` to the grid 41 of the-green gun forming the green spot'36.

v Ank alternative form of the screen in Fig. l is illustrated in Figs; 5 and 6. This screen operates in substantially the same manner as that illustrated in Fig. l with the exception that the secondary emission producing means is located between twov adjacentl series of color strips trated in Figs-Zand 3, and` described earlier in thisispecication. In this embodiment, the secondary emission producing means comprises a lm of aluminum which needbe neither light-reecting nor electron passing, and which is formed as a seriesofstrips 13(b) aligned between each of the colorelements 9(1)) and 11(b). The several strips `13(b) are connected together and are con nected to the anode 15(b) ofthe tube. Other than for these changes in structure, the mode of operation of this tube is the same as lthat depicted earlier in this application. This type of` screen is equally applicable to the single and to the lthree gun'tube.

An alternative form of electron collecting means is illustrated in Figs. 7, 8 and 9 wherein the elements containing, thesuiiix (c) areidentical to the corresponding elements in the prior embodiments of this invention.v In this embodiment, however, the secondary electron collecting means -14 is replaced with secondary emission collecting means 14(c). The collector `14`(c) comprises a wire mesh having a spacing of, say, one-half inch or greater between themeshes. This collector is placed inwardly from the color screen 8(0) of the tube so that the shadow which might otherwise be produced by the beam or beams passing through it will be out of focus on the screen. The collector 14(c) is insulated from the anode 150:) by means of insulators l6(c) and is provided with a terminal 17(0) for connecting the collector to the circuit. This alternative may be used either with the single or the three gun tube and may be used in connection with either of the alternative forms of picture screen illustrated above.

Obviously this invention is not limited to the specific structure shown Vin the drawings and described in they specification, 'but itis capableof numerous other modications and changes without departing from the spirit and scope thereof. Said invention should be limited by the scope of the appendant claims.

Having'thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A cathode ray.V tube Yfor color television of the type having a cathode ray generating means and a translucent screen having a plurality of parallel color lines arranged in a repetitive series of lines having diiferentcolor characteristics `so as to be sequentially scanned by electrons eminating from the cathode ray generating means, the combination of; a layer of electron permeable material covering the face of said color lines facing the cathode ray generating means consisting solely of material having a rate of secondary emission less than the color lines and a plurality of conductive electron permeable light reective lines arranged in parallelism with each other and with the color lines'formed of material providing substantially more secondary emission when subjected to electron bombardment than the color lines, means for collecting the secondary vemission produced by the impingement of electrons upon said conductive lines whereby an indexing pulse s formed to designate the relative location of the electrons with respect to the several color lines on the translucentpscreen, said conductive lines being positioned to provide secondary emission to produce an indexing pulse keyed to the color lines of one color in the repetitive series of color lines and to reliect light from latter color lines toward the viewing face of the cathode ray tube, and the cathode ray generating means comprising a plurality of electronVguns-each operative in association with the color lines of one Vcolor in the repetitive series of color lines to emit a greater ow of electrons during time intervals when the respective said guns are registered with the color line ofthe respective colors in the repetitive series of color lines. v

2. In fa cathode ray tube for color television of the type having cathode ray generating means and a translucent screen having a plurality of parallel luminescent color lines arranged to be sequentially scanned by elec'- trons emanating from the cathode ray generating means,

" nal, said iirst signal being disposed to cause said electron the combination of; a plurality of electron permeable lines arranged in parallelism with each other and the color lines, said electron permeable lines formed of material providing substantially more secondary emission lduced by the 4impingement of electrons upon said electron permeable lines whereby an indexing pulse is formed to designate the relative location of the electrons with respect tot-hecolor lines in the translucent screen, said cathode rayk generating means comprising a tirst cathode ray gun and a pair of second cathode ray guns, said rst cathode ray gun :constructed` and arranged to produce iirst and second signals, saidrsecond cathode ray guns being constructed and arranged to produce a second sigpermeable lines to emit sufficient secondary emission to createV an indexing pulse on the collecting means, and said second signals disposed to cause said color lines to illuminate.

3. A cathode ray tube according to claim 2 and wherein said first cathode lray gun is disposed to provide the first-signal with a substantially predetermined lead. over the second signal produced by said second cathode ray guns.

4. In a system of color television for reproducing a colored image from a plurality of different color signals the combination of a cathode ray tube including cathode ray generating means, a translucent screen having a plurality of parallel luminescent color lines arranged in a repetitive series of lines having a diierent color characterirstic so as to be repetitively scanned by electrons from said cathode ray generating means, a plurality of electron permeable lines arranged Iin association with the color line of one color in said repetitive series of color lines and in parallelism therewith, said electron permeable lines formed of material providingl substantially more. secondary emission when subjected to electron bombardment tha-n the color lines, means for collecting the secondary emission produced by the impingement of electrons upon said conductive lines whereby an indexing pulse is formed to designate the relative location of electrons with respect to the several color lines in said translucent screen, said electron permeable lines positioned to cause secondary emission therefrom to cause the indexing pulse to issue when said ray generating means impinges electrons on the lines of one color in said repetitive series of color lines, said cathode ray generating means comprising a plurality of electron beam signal generating guns comprising a rst gun arranged to produce a rst and second signal and a pair of second guns arranged to produce second signals, each gun arranged in operative association with the color lines of one color -in the repetitive series of color lines wherein the second signal lfrom each gun is responsive to thecolor signal representative of one color when the said gun is registered with the color line corresponding thereto, and said first signal is responsive to produce sufiicient secondary emission from said conductive lines to yform an indexing pulse to designate the relative locations of electrons with respect to the several colorlines in said translucent screen, said first signal from said rst gun being disposed to lead the second signals from Ysaid second guns a predetermined phase interval. e

5. A cathode ray tube for color television including a translucent screen having a plurality of luminescent color lines arranged at right angles to the direction of scanning travel of a cathode ray in sa-id tube; said parallel color lines comprising a repetitive series of lines having different coloqcharacteristics; a light reflective coating over i Y only each of a Vfirst one color in said repetitive series of color lines; said coating producing secondary emission upon impingement of a cathode ray in said tube and havondary emission iproducedby' the impingeme't of a cathode ray upon saidV reilective 'coating whereby a pulse is. formed imparting the relative location ofthe cathode ray. beam with respect to the rstcolor lines in said translucent` screen. y

6. A cathode ray tube `according to c laiin 5 and whereinsaid means for collecting secondary emission comprises a screen positioned in parallel alignment relative to said translucent screen. v

7. In a cathode ray tube for color television of the type having cathode ray generating means 'and a translucent screen havingy ya plurality of parallel luminescent color lines arranged' to be sequentially Scanned' by elec-- trons eminating `from the cathode ray'generatingmeans,

the combination of: an electron permeable lightreect-- secondary emission when subjected to electron bernhard-- mentthan the color lines; means for collecting secondary emission producedby the impingement of electrons upon said coating' wherebyv anindexing pulse is formedto designate the relative location of the. electrons with. respect to the color lines in the `translucent screen.

References Cited in `the le of this patent UNTED STATES PATENTS 2,545,325 Weimer Mar. 13', 1951 2,644,855 Bradley July 7, 1953 2,648,722 Bradley Aug. 11, 1-953 2,667,534 Creamer Jan. 26, 1954 2,671,129 Moore Mar. 2, 1954 2,681,381. Creamer June 15,1954 2,689,269 Bradley; Sept. 14, 1954 2,689,927 Bradley Sept. 2l, 1954v 2,743,312 Bingley Apr. 24, 1956 Hergenrother May 7, 1957 

